1. Field of the Invention
The invention relates to a semiconductor body and somewhat more particularly to a method of doping select zones of a semiconductor body and a transistor so-produced.
2. Prior Art
At the present time, there are basically two processes for producing semiconductor components with doped zones therein. One is by diffusion and the other is by ion implantation.
In a diffusion process, the concentration of a dopant on the surface of a semiconductor body and the dopant profile or distribution therein is determined by the solubility of the dopant in the semiconductor body, the select diffusion temperature and the diffusion procedure employed. A typical procedure is, for example, to split up the doping process into a first step of coating a determinate quantity of dopant onto a select surface zone of a semiconductor body and, a second step of diffusion dopant from the coating into the semiconductor body in order to set the position of the pn-junction. Because of the generally very high concentration of dopant atoms on the surface of a so-treated semiconductor body, lattice distortions tend to occur and detract from the desired characteristics of the resultant semiconductor body.
High dopant concentrations on the surface of a semiconductor body may be avoided by ion implantation doping because in this type of doping process the quantity and position of the dopant atoms are determined by the ion energy and implantation dosage utilized. However, the implanted ions or atoms cause lattice disturbances due to beam damage, which must be healed or removed by a subsequent heat treatment. At high implantation dosages (i.e., dopant concentrations greater than 10.sup.18 cm.sup.-3), such beam damage, which is often in the form of so-called "damage complexes" (for example, in the form of a combination of a lattice vacancy and an oxygen atom), can only be fully removed at relatively high temperatures, i.e., above 1000.degree. C.